Clamp device for securement of scaffolding to large-girth structures

ABSTRACT

Clamp device ( 10 ) for attaching scaffolding or the like apparatus to a large-girth structure (LDP). An elongated base ( 18 ) is positioned transversely across the girth. It carries stand-offs ( 22   a,    22   b ) for spacing the base from the girth. Attachments ( 46   a,    46   b ) for the scaffolding are at opposite ends of the base. Length-adjustable securement members ( 24   a,    24   b ) are carried near opposite ends of the base. A flexible elongated girth-encircling member ( 44 ), such as a high-strength chain, is extended around the girth, with length adequate for connection to the second securement members which are selectively adjustable in length from the base to cinch the girth-encircling member into tensile condition securely gripping to the girth by tightening adjustment. These adjustable members swing relative to the base so that during their tightening, portions of the length of the girth-encircling member become tangent to points on the girth.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of U.S. provisional patentapplication Ser. No. 60/592,576, filed Jul. 30, 2004, entitled CLAMPDEVICE FOR SECUREMENT OF SCAFFOLDING TO LARGE-GIRTH STRUCTURES.

BACKGROUND OF THE INVENTION

The invention relates to scaffolding and related structures and, moreparticularly, to apparatus for securement of scaffolding, walkways andother scaffolding and other access components or apparatus tolarge-girth structures such as large diameter pipes, columns and otherstructural components used for example in oil rigs and platforms.

Off shore oil rigs and platforms are of immense size and height, beingtypically enormous structures of steel or concrete members standing onthe sea floor, or in some cases, floating rigs or structures held inplace by cables attached to a sea floor or otherwise anchored. Thesestructures often include steel pipes or tubes having diameters up toseveral feet in diameter (e.g. up to 12 feet). It is desired to be ableto provide scaffolding on or around the large structural members,sometimes at dangerous heights far above ground or water level. Thesestructural members may be vertical, horizontal, sloping, oblique, orotherwise variably oriented, providing an extreme challenge for thetypically temporary securement of the scaffolding or walkways on oraround them. The large-girth tubular structures can be referred toherein simply as large diameter pipes (LDPs). Their girth, like theirorientation, is subject to great variation. For example, diameters ofsuch LDPs may vary from several inches to many inches or to severalfeet, e.g. to as much as 12 ft., implying a girth of nearly some 40 ft.In some cases, LDPs may be tapered, so their diameter may vary overportions of their lengths.

Heretofore, securement of scaffolding or walkways on or in proximity toan LDP often involved the need to weld brackets or scaffoldingsecurement components to the LDPs. This is, to say the least, very timeconsuming and expensive. It also typically means that when scaffoldingis to be removed the bracket or other components welded to an LDP mustbe cut free, as by using a cutting torch. Then, the location of thebracket or component must be resurfaced by grinder followed byapplication of paint or other protective coating. Risk to workers isinvolved in such operations.

What has instead long been needed, a need which has long been unfilled,is a safe and easy-to-use clamp arrangement, a clamp device, for quicksecurement of scaffolding or other access apparatus (e.g., ladders orwalkways) on or around LDPs or other large-girth structural members,such as the LDPs used for off shore oil rigs, and which will allowscaffolding or other access apparatus to be quickly and securelyattached without damage to the LDP or other tubular structure, andavoiding the need for welding or otherwise altering an LDP or comparablestructure, as well as allowing quick removal. Yet also, and mostimportantly, there has been a need to provide such a clamp arrangementwhich gives an ample human safety factor in use, and so allow workers toclimb safely on or around the scaffolding while providing easy and safeaccess to the LDP or other large-girth structure.

Safety is a critically important issue in the matter of usingscaffolding and access structures on immense LDPs of the type used inoil rigs, where workers may find themselves 200 feet or even 300 feetabove sea level or other surfaces.

For convenience, in this description, the term LDP is used to refer toany large-girth structure to which the presently disclosed inventiveapparatus may be secured. For purposes of the present disclosure, suchan LDP may be solid, tubular, man-made or natural, and may includestructures such as beams of concrete or composite materials, columns(e.g., of rock or masonry or metals), and even organic structures suchas trees. So also, for convenience, the presently inventive apparatusmay be referred to sometimes as a large diameter pipe clamp (“LDPC”) orsimply as a “clamp.”

SUMMARY OF THE INVENTION

Accordingly, among objects of the invention are to provide a clamp fortypically temporary securement of scaffolding or other access apparatusto an LDP quickly and easily, and with a high degree of safety; whichallows such a construction to be removed without damage to an LDP; whichcan be installed and removed easily; which can be used for variousorientation of the LDP, whether vertical, horizontal or oblique; and nomatter whether the LDP pipe or other structure is tapered, irregularlyshaped, varying in diameter, or of circular solid or tubular section, orotherwise having different geometry, but otherwise providing a largegirth; and which can be installed also on columns, beams andunusually-shaped structures, such as non-tubular structures, includingalso bridge elements, concrete columns, rock columns, industrialchimneys, and various man-made structures, as well as possibly alsonatural structures such as stone or large trees; and which in generalprovides safe and easy installation regardless of the surface or varyingshape of LDPs.

Among other objects of the invention may be noted the provision of sucha clamp which can be used for purposes for other than securement ofscaffolding, such as for example, the securement of walkways, ladders,auxiliary apparatus and devices, to an LDP, whether used as a singleclamp or as used in multiple or tandem clamp installations.

Briefly, a clamp or clamp device of the invention is provided forattaching scaffolding or the like apparatus to any of such variouslarge-girth structures (LDP). An elongated base is positionedtransversely across the girth. It carries stand-offs for spacing thebase at least a small distance from a portion of the girth. Attachmentsfor the scaffolding are provided at opposite ends of the base.Length-adjustable securement members, accessible to an installing workerinwardly of the scaffolding attachments, are carried also near oppositeends of the base. A flexible elongated girth-encircling member, such asvery high-strength chain, is extended around the girth in encirclingrelation, having length adequate for connection to the securementmembers which are selectively adjustable in length from the base by aninstaller so as to cinch the girth-encircling member into tensilecondition securely gripping the girth by tightening adjustment. Theseadjustable members can each swing relative to the base so that duringtightening, portions of the length of the girth-encircling member becometangent to points on the girth.

More specifically, the clamp or clamp device of the invention providestypically temporary clamping attachment of scaffolding apparatus orother access apparatus to any one of possible large-girth structures(LDPs) having a girth which could vary over a substantially great rangeand having an orientation which also could vary, comprises a linearlyelongated rigid support base for being positioned in proximity to such alarge-girth structure in generally perpendicular relation thereto. Astand-off contacts points partly around the girth of such large-girthstructure for spacing the base from said girth in proximity to apreselected location on said girth. Attachments are carried at oppositelocations along the base proximate opposite ends thereof for attachmentof said apparatus, as for coupling to scaffolding members. First andsecond elongated length-adjustable securement members are carried by thebase at opposite positions along an axis of elongation of the baseproximate opposite ends of the base. At least one flexible elongatedgirth-encircling tensile gripping member is provided. It is used byextension around said girth at said preselected location in grippingrelation to said girth, and it has a length adequate for affixment ofportions thereof at opposite ends to the first and second securementmembers to provide encircling gripping relation to said girth. Thesecurement members are selectively adjustable in length relative to thebase. They allow cinching the girth-encircling member or members intotightness, i.e., tensile condition, to secure said gripping relation tothe girth by tightening adjustment in length. The securement members arepivotally carried by the base, each being swingably affixed to the baseto permit each of them to swing such that during their tighteningadjustment, portions of the length of the girth-encircling member whenin tensile, gripping relation to the girth, come into tangency with thegirth.

The new clamp thereby provides clamping attachment of scaffoldingapparatus or other access apparatus to such large-girth structurereliably securely and safely for worker use.

Other objects and features will be apparent or will be understood fromthe following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a clamp device in accordance with and embodyingthe present invention, and depicting its use for clamping engagement ofany of several possible large-girth structures, or LDPs.

FIG. 2 is an end view of portions of a base of the clamp device.

FIG. 3 is a top view of the base.

FIG. 4 is an assembly drawings, in side elevation, of a disassembledlength-adjustable securement member, being one of a pair such memberspivotally carried by a base of the clamp device.

FIG. 5 shows multiple use of clamp device of the invention positionedabout LDPs.

FIG. 6 shows installation of clamp device of the invention on LDPportions of a rig before it is lifted into position.

FIG. 7 shows multiple installation of the new clamp devices forhorizontal LDP installation to support access walkway.

FIG. 8 shows the inventive clamp devices high aloft rig members havingLDPS, supporting scaffolding in place as interconnected LDPs as part ofa rig are lifted into position.

FIG. 9 shows a rig unit consisting of interconnected LDPs including ascaffolding assembly supported by a clamp device of the invention.

FIG. 10 is a view, on the ground, of a base of clamp device of theinvention, resting on a pallet, to show components.

Corresponding characters indicate corresponding elements in the views ofthe drawings.

DESCRIPTION OF A PRACTICAL EMBODIMENT

Referring now to the drawings, particularly the FIG. 1, the new clampdevice is designated generally 10. It is here shown as it may beattached to one of several large-girth structures (LDPs). For example, a30-in. pipe (where the dimension refers to the diameter) is designatedat 12, a 7 ft. diameter pipe is 14 and a 12 ft. diameter pipe is at 16.Clamp 10 can be used with any of such large-girth structures fortemporary clamping attachment of scaffolding apparatus or other accessapparatus (such as catwalks, access ladders, and various possibledevices and structures) to any one of possible such LDPs, where thegirth could vary over substantially great range such as from a few feetto more than 40 feet, if not greater, and where the orientation of sucha structure could also vary, as for example, being vertical, horizontalor oblique, or where the diameter may vary from one end to the other asin a tapered LDP. Therefore, it will be understood that the variety oflarge-girth structures with which the new clamp device can be used isalmost unlimited in scope, and may include objects and structures whichare not necessarily tubular, or not pipes, or are not necessarilycircular in shape, but instead irregularly shaped, and otherwise ofdifferent geometry, but in any event having a large girth such astypical of big columns, large pipes, structural beams and evenunusually-shaped structures such as bridge elements, concrete columns,rock columns, chimneys as well as natural formations and various manmadestructures.

The new device is provided with a linearly elongated rigid support basegenerally designated 18 and which is formed, as seen in FIG. 2 comparedwith FIG. 1, of a steel channel member 18 which opens downwardly with arectangular configuration, and so provides an LDP-engaging supportsurface. Channel 18 may be several inches in width, and 6 inch width ispreferred. The axis elongation of channel member 18 in intended to belocated in general perpendicular relation to the large-girth structureor LDP. That is, as seen in FIG. 1, it will extend across a sideservice, in lateral relation, to the LDP. Provided at the lower edge ofthe U-shaped channel member 18 are a pair of tubular members 22 a, 22 bas stand-offs carried by the base for contacting at least two spacedpoints around the girth of the LDP for spacing the base at leastslightly from the girth in proximity to a pre-selected location on thegirth at which a scaffolding apparatus or other access apparatus (ordevice) is desired to be attached in clamped relationship. Thesestand-offs 22 a, 22 b, as seen in FIG. 2, may be transversely-orientedlengths of steel scaffold tubing. They may be, for example, about 1 ft.in length to provide a stable lateral support surface for contacting thereferenced points on the girth of the LDP. The stand-offs may instead bevarious other spacing structures and of various materials, includingmetals and nonmetals suitable for engaging the LDP to maintain properspacing and contact.

As shown in FIG. 1, the stand-offs bring the base 18 in close proximityto the LDP but provide a at least small clearance, as may be sufficientand useful to allow wires, lines, cables, conduits, transmission linesor small pipes, hoses or tubing to run along the length of the LDPbeneath the base without requiring their relocation during work whileclamp 10 remains attached.

Base 10 is to be secured in relation to an LDP by a pair of elongatedlength-adjustable securement assemblies 24 a, 24 b which are formed, asseen in FIG. 4, by a threaded rod end 28 in which a double clevis link26 is attached to the eye end by a pin or bolted securement. Further,the double clevis link 26 is attached to a chain hook 32 by a pin orbolted securement. The upper end of the rod end 28 is threaded at itsupper end which engages a relatively large diameter (e.g., 2 in.) lengthof bar stock 36 which may have a length of several inches. It is centerbored to accept the upper end of threaded rod end 28 and a nut 38 andbeneath a washer 39. Since rod end 28 extends above the base, theexposed head or nut 38 allows convenient and safe tightening of theassembly by an installation worker at base 18, and so allow therespective members 24 a, 24 b to be adjusted in length. Members 24 a, 24b extend through apertures of 40 a, 40 b as seen in FIG. 3, provided inbracket assemblies 49 a, 49 b which are located toward the oppositeouter ends of base 18. Apertures 40 a, 40 b may be loosely slotted byelongation along the base axis so as to allow swinging, pivoted,movement of assemblies 24 a, 24 b to a substantial angle such aspreferably at least through 90 degrees, or even 120 degrees, generallyas can be appreciated from FIG. 1. These first and second elongatedlength-adjustable securement members allow tensioning of a very highstrength chain designated generally at 44 which is intended to be passedaround the girth of the large-girth LDP such as that illustrated at 12,14 or 16, and with the length of the chain being dependant upon thediameter of the LDP and/or its girth. For example, a chain length of12.5 ft. fits a pipe diameter in the range of 30 in. to 4 ft., a chainlength of 22 ft. accommodates a pipe diameter of 5-7 ft. and a chainlength of 40 ft. accommodates the girth of a LDP of pipe diameter 8-12ft. The opposite ends will be carried by the respective hooks at thelower ends of the length-adjustable members 24 a, 24 b.

These members 24 a, 24 b will be adjusted by a user during installationof the new pipe clamp to bring chain 44 into tensile, gripping relationwith the LDP girth of the LDP to tightly clamp base 18 to the LDP forthe purpose of carrying scaffolding structure or other access apparatusor devices, such as walkways and the like. For that purpose, lengths ofscaffold tubing are shown at 46 a, 46 b, and they extend inperpendicular relation upwards from the main component of base 18. Theyare securely welded and strengthened by webs or gussets as at 48.

The new pipe clamp may be installed on an LDP which is part of a rig asit is assembled on the ground, or it may be installed in the air, highaloft in a oil well rig, being both easily installed as well as easilyremoved by adjustment of the first and second length-adjustablesecurement members 24 a, 24 b.

It is to be understood that as the nut head 38 of each such tighteningassembly is tightened during installation, e.g., to a torque of mostpreferably 120 foot-pounds, chain 44 comes into tightly-grippingrelationship about the girth of an LDP. As the tightening takes place,these adjustment assemblies are free to pivot about head 36, until endportions of chain 44 come into tangency with points on the surface ofthe LDP girth; and each head is very securely maintained in stablelongitudinal position on base by L-shaped angle brackets as at 49 a, 49b welded in place.

The high strength of chain 44 can best be obtained by specifying chaingrade 80, heat treated alloy steel chain, rated for overhead use, thechain having a typical minimum tensile strength or capacity of 12,000lbs. which will be found adequate for LDP diameter ranges herementioned. So also, other hardware components of the new clamp device orassembly are preferred or specified to be grade 80 or better; with allsteel components grade A36 or better, and all welds to specification ofAWS D1.1. It is preferably to be specified that all parts except thechain should be hot dip galvanized.

The manner of using the new clamp device is illustrated in FIGS. 5-9.

FIG. 5 shows an LDP 50 having a main end diameter but larger diameter 51and with multiple clamp devices 10 positioned about the lower mainportion, and carrying a scaffold assembly 52.

FIG. 6 demonstrates the applicability of a clamp device of the inventionapplied to such LDP 50 while the LDP is horizontal and at ground level,and with the scaffolding 52 in place about LDP 50 provided by clampdevice 10, in readiness for lifting of the LDP as part of a rig.

FIG. 7 illustrates a horizontal LDP 54 of substantially constantdiameter provided with a pair of clamp devices 10 of the invention, andsupporting a ladder walkway 56 including scaffolding members andsupported by both clamp devices 10.

FIG. 8 demonstrates the application of a clamp device 10 high aloft rigmembers having LDPs, and with scaffolding 62 in place as interconnectedLDPs as part of a rig are lifted into position, and illustrating usethereby of the new clamp device with scaffolding to form a hangingplatform.

FIG. 9 illustrates a rig unit consisting of interconnected LDPsincluding a scaffolding assembly 66 supported by a clamp device of theinvention about an LDP 68, and the rig being shown as it is lifted intointended position.

FIG. 10 illustrates the simplicity of the base 18 including the pivotassemblies 36 and threaded rod members 38 extending from the base, andshowing the relative motion provided by base 18 or pivotal movement ofthe pivoted extendable length members.

It should be understood that instead of chain 44, a clamp device of theinvention can be secured by various possible alternative flexibleelongated girth-encircling members, such as multiple lengths ofhigh-strength chain, wire cable or rope assemblies consisting ofnumerous strands of cabling, and/or combinations of the foregoing, asmay be desired for engagement of the girth of an LDP or otherlarge-girth structure so as to provide a secure encircling grippingrelation to the girth.

As various modifications could be made in the constructions hereindescribed and illustrated without departing from the scope of theinvention, it is intended that all matter contained in the foregoingdescription or shown in the accompanying drawings is to be interpretedas illustrative rather than limiting. Thus, the breadth and scope of thepresent invention should be defined only in accordance with thefollowing claims and their equivalents.

1. A clamp device for temporary clamping attachment of scaffoldingapparatus or other access apparatus to one of possible large-girthstructures having a girth which could vary over a substantially greatrange and having an orientation which also could vary, comprising: alinearly elongated rigid support base f or being positioned in proximityto such a large-girth structure in generally perpendicular relationthereto; a stand-off carried by the base for contacting at least twospaced points around the girth of such large-girth structure for spacingthe base from said girth in proximity to a preselected location on saidgirth at which said apparatus is desired to be attached; attachmentmeans carried at opposite locations along the base proximate oppositeends thereof for attachment of said apparatus; first and secondelongated length-adjustable securement members carried by the base atopposite positions along an axis of elongation of the base proximateopposite ends of the base; at least a first flexible elongatedgirth-encircling member for extension around said girth at saidpreselected location in gripping relation to said girth, thegirth-encircling member having a length adequate for affixment ofportions thereof at opposite ends to the first and second securementmembers to provide encircling gripping relation to said girth; the firstand second securement members being selectively adjustable in lengthrelative to the base by adjustment at the base for cinching thegirth-encircling member into tightness to secure said gripping relationto the girth by tightening adjustment in their length; the first andsecond securement members each being swingably affixed to the base topermit each to swing in a plane which includes the axis of elongation ofthe base such that during said tightening adjustment of the first andsecond securement members, portions of the length of thegirth-encircling member come into tangency with the girth; whereby theclamping attachment of scaffolding apparatus or other access apparatusto such large-girth structure is reliably secure and safe for workeruse.
 2. A clamp device for attaching scaffolding, support, or accessapparatus to a large-girth structure, the device comprising: a base ispositioned transversely across the girth, stand-off means carried by thebase for spacing the base from the girth, means carried at oppositelocations on the base for attachment to said apparatus,length-adjustable securement members are also at opposite points of thebase, a flexible elongated girth-encircling member to be extended aroundthe girth, with length adequate for connection to the securement memberswhich are selectively adjustable in length from the base so as to cinchthe girth-encircling member into tensile condition securely gripping tothe girth by tightening adjustment. the length-adjustable securementmembers being movable by pivoted movement relative to the base so thatduring tightening, portions of the length of the girth-encircling memberbecome tangent to points on the girth.
 3. A clamp device for attachmentof scaffolding or other apparatus to one of possible large-girthstructures having a girth which could vary over a substantially greatrange and having an orientation which also could vary, comprising: alinearly elongated rigid support base for being positioned in proximityto such a large-girth structure in generally perpendicular relationthereto. stand-off carried by the base and contacting points partlyaround the girth of such large-girth structure for spacing the base fromsaid girth in proximity to a preselected location on said girth,attachment points carried by the base at opposite locations along thebase proximate opposite ends thereof for attachment of said apparatus,first and second elongated length-adjustable securement members carriedby the base at opposite positions along an axis of elongation of thebase proximate opposite ends of the base, at least one flexibleelongated girth-encircling tensile gripping member for extension aroundsaid girth at said preselected location in gripping relation to saidgirth, and having a length adequate for affixment of portions thereof atopposite ends to the first and second securement members to provideencircling gripping relation to said girth, the securement members beingselectively adjustable in length relative to the base for cinching thegirth-encircling member or members into tensile condition for securingsaid gripping relation to the girth by tightening adjustment in theirlength, the securement members being pivotal relative to the base toallow them to swing such that during their tightening adjustment suchthat portions of the length of the girth-encircling member, when intensile, gripping relation to the girth, become tangent to locations ofsaid girth, whereby the clamping attachment of scaffolding apparatus orother access apparatus to such large-girth structure is reliably secureand safe for worker use.
 4. A clamp device as set forth in claim 3, thesecurement members each being swingably affixed by being pivotallycarried by the base to the base to permit each to move swingably in aplane which includes the axis of elongation of the base.
 5. A clampdevice as set forth in claim 4, the securement members each beingconstituted by a tightening rod which includes a threaded portion whichextends into a corresponding bar carried by the base, and a tighteningdevice engaging the threaded portion to permit selective tightening ofthe rod relative to the base by drawing the rod threaded portion towardthe base.
 6. A clamp device as set forth in claim 3, each tightening rodhaving a rod end portion carrying threads which extend above the base toallow allows convenient and safe tightening of the assembly by aninstallation worker.
 7. A clamp device as set forth in claim 6, whereinthe tightening device is a nut threaded onto the rod threads above thebase so as to be accessible by such installation worker for tighteningof the nut.
 8. A clamp device as set forth in claim 5, wherein suchlarge-girth structure has an structure axis of elongation, and whereineach corresponding bar is axially elongated and includes a bar axisparallel to the structure axis of elongation.
 9. A clamp device as setforth in claim 5, wherein the base has an axis of elongation and eachcorresponding bar is slotted by elongation along the base axis ofelongation so as to allow swinging, pivoted, movement of the respectivetightening rod through a substantial angle of at least through 90degrees.
 10. A clamp device as set forth in claim 3 wherein the tensilegripping member is carried by and extends the securement members andcomprises high-strength chain.
 11. A clamp device as set forth in claim3 wherein the chain is grade
 80. 12. A clamp device as set forth inclaim 3 wherein the tensile gripping member is carried by and extendsthe securement members and comprises high-strength chain, wire cable orrope assemblies consisting of numerous strands of cabling, orcombinations of the foregoing.